Merge branch 'b9005' into 2.13.x

Author: szeiger

test/junit/scala/collection/mutable/QueueTest.scala

@@ -15,4 +15,18 @@ class QueueTest {
     val q2: Queue[Int] = q1.reverse
     assertEquals("Queue", q2.className)
   }
+
+  @Test
+  def t9005(): Unit = {
+    val q = Queue(1, 2, 3)
+    assertEquals(q, List(1, 2, 3))
+    val r = q.tail
+    assertEquals(r, List(2, 3))
+    assertEquals(q.enqueue(4), List(1, 2, 3, 4))
+    assertEquals(r, List(2, 3))
+    val s = q.drop(1)
+    assertEquals(s, List(2, 3, 4))
+    assertEquals(q.enqueue(5), List(1, 2, 3, 4, 5))
+    assertEquals(s, List(2, 3, 4))
+  }
 }